2002 YAMAHA YZ125LC oil

4-71
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H4801
Shift fork, shift cam and segment
1. Inspect:
9Shift fork 1
Wear/Damage/Scratches Replace.
2. Inspect:
9Shift cam 1
9Segment 2
9Guide bar 3
Bend/Wear/Damage Replace.
3. Check:
9Shift fork movement
On its guide bar.
Unsmooth operation Replace shift fork
and/or guide bar.
NOTE:
For a malfunctioning shift fork, replace not only
the shift fork itself but the two gears each adja-
cent to the shift fork.
EC4H5000
ASSEMBLY AND INSTALLATION
EC4H5213
Transmission
1. Install:
95th pinion gear (23T) 1
93rd pinion gear (19T) 2
94th pinion gear (19T) 3
92nd pinion gear (17T) 4
To main axle 5.
NOTE:
9Apply the molybdenum disulfide oil on the 4th
and 5th pinion gears inner circumference and
on the end surface.
9Apply the molybdenum disulfide oil on the 2nd
and 3rd pinion gears inner circumference.
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4-72
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
2. Install:
93rd wheel gear (29T) 1
94th wheel gear (24T) 2
92nd wheel gear (31T) 3
95th wheel gear (25T) 4
91st wheel gear (27T) 5
To drive axle 6.
NOTE:
9Apply the molybdenum disulfide oil on the 1st,
2nd and 3rd wheel gears inner circumference
and on the end surface.
9Apply the molybdenum disulfide oil on the 4th
and 5th wheel gears inner circumference.
3. Install:
9Plain washer 1
9Circlip 2
NOTE:
9Be sure the circlip sharp-edged corner ais po-
sitioned opposite side to the plain washer and
gear b.
9Be sure the circlip end cis positioned at axle
spline groove d.
4. Install:
9Spacer 1
NOTE:
9Apply the lithium soap base grease on the oil
seal lip.
9When installing the spacer into the crankcase,
pay careful attention to the crankcase oil seal
lip.
5NY-9-30-4D 5/24/01 8:33 PM Page 32

4-73
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H5312
Shift cam and shift fork
1. Install:
9Shift fork 1 (L) 1
9Shift fork 2 (C) 2
9Shift fork 3 (R) 3
NOTE:
9Mesh the shift fork #1 (L) with the 4th wheel
gear 4and #3 (R) with the 5th wheel gear 6
on the drive axle.
9Mesh the shift fork #2 (C) with the 3rd pinion
gear 5on the main axle.
2. Install:
9Shift cam 1
NOTE:
9Apply the transmission oil on the shift cam.
9Install the shift cam while holding up the 4th
wheel gear 2and keeping the shift fork #1 3
moved in the direction of the arrow.
3. Install:
9Guide bar (short) 1
9Guide bar (long) 2
NOTE:
9Apply the transmission oil on the guide bars.
9Be sure the long bar is inserted into the shift
forks #1 and #3 and the short one into #2.
5. Install:
9Main axle 1
9Drive axle 2
NOTE:
Apply the transmission oil on the crankcase
bearings.
5NY-9-30-4D 5/24/01 8:34 PM Page 34

5-1
CHASFRONT WHEEL AND REAR WHEEL
Extent of removal Order Part name Q’ty Remarks
FRONT WHEEL REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
1 Hose cover 1
2 Bolt (brake hose holder) 2 Only loosening.
3 Bolt (axle holder) 4 Only loosening.
4 Nut (front wheel axle) 1
5 Front wheel axle 1
6 Front wheel 1
7 Collar 2
8 Oil seal 2
9 Bearing 2 Refer to “REMOVAL POINTS”.
10 Brake disk 1
EC500000
CHASSISEC590000
FRONT WHEEL AND REAR WHEELEC598000
FRONT WHEEL
2
13
3
Extent of removal:1Front wheel removal2Wheel bearing removal3Brake disc removal
w
Support the machine securely so there is no dan-
ger of it falling over.
5
23 Nm (2.3 m•kg, 17 ft•lb)
23 Nm (2.3 m•kg, 17 ft•lb)
105 Nm (10.5 m•kg, 75 ft•lb)
16 Nm (1.6 m•kg, 11 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)12 Nm (1.2 m•kg, 8.7 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
5NY-9-30-5A 5/23/01 9:00 PM Page 2

5-2
CHASFRONT WHEEL AND REAR WHEEL
EC598100
REAR WHEEL
Extent of removal:1Rear wheel removal2Wheel bearing removal3Brake disc removal
Extent of removal Order Part name Q’ty Remarks
REAR WHEEL REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
1 Nut (rear wheel axle) 1
2 Rear wheel axle 1
3 Chain puller 2
4 Rear wheel 1 Refer to “REMOVAL POINTS”.
5 Collar 2
6 Driven sprocket 1
7 Oil seal 2
8 Circlip 1
9 Bearing 2 Refer to “REMOVAL POINTS”.
10 Brake disk 1
2
13
3
w
Support the machine securely so there is no dan-
ger of it falling over.
125 Nm (12.5 m•kg, 90 ft•lb)
14 Nm (1.4 m•kg, 10 ft•lb)
42 Nm (4.2 m•kg, 30 ft•lb)
5NY-9-30-5A 5/23/01 9:00 PM Page 4

5-3
CHASFRONT WHEEL AND REAR WHEEL
EC593000
REMOVAL POINTS
EC523101
Rear wheel
1. Remove:
9Wheel 1
NOTE:
Push the wheel forward and remove the drive
chain 2.
EC513201
Wheel bearing (if necessary)
1. Remove:
9Bearing 1
NOTE:
Remove the bearing using a general bearing
puller 2.
EC594000
INSPECTION
EC514100
Wheel
1. Measure:
9Wheel runout
Out of limitRepair/Replace.
2. Inspect:
9Bearing
Rotate inner race with a finger.
Rough spot/SeizureReplace.
NOTE:
Replace the bearings, oil seal and wheel collar
as a set.
Wheel runout limit:
Radial
1 1
: 2.0mm (0.08 in)
Lateral 2 2
: 2.0mm (0.08 in)
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5-3
CHAS
ROUE AVANT ET ROUE ARRIERE
VORDERRAD UND HINTERRAD
RUOTA ANTERIORE E RUOTA POSTERIORE
AUSBAUPUNKTE
Hinterrad
1. Ausbauen:
9Rad 1
HINWEIS:
Das Rad nach vorne stoßen und die
Antriebskette 2abnehmen.
Radlager (wenn erforderlich)
1. Ausbauen:
9Lager 1
HINWEIS:
Das Lager unter Verwendung einer
allgemeinen Lager-Abziehvorrichtung
2ausbauen.
INSPEKTION
Rad
1. Messen:
9Felgenschlag
Außerhalb des Grenzwertes
Reparieren/Erneuern.
2. Prüfen:
9Lager
Den inneren Laufring mit
einem Finger drehen.
Rauhe Stellen/Freßspuren
Erneuern.
HINWEIS:
Die Lager, die Öldichtung und die
Radhülse als Satz erneuern.
POINTS DE DEPOSE
Roue arrière
1. Déposer:
9Roue 1
N.B.:
Pousser la roue vers l’avant et déposer
la chaîne de transmission 2.
Roulement de roue (si nécessaire)
1. Déposer:
9Roulement 1
N.B.:
Déposer le roulement en utilisant un
arrache-roulement courant 2.
VERIFICATION
Roue
1. Mesure:
9Voile de roue
Hors limiteRéparer/Changer.
2. Examiner:
9Roulement
Faire tourner la bague intérieure
avec le doigt.
Point dur/grippage’Changer.
N.B.:
Changer les roulements, la bague
d’étanchéité et la collerette de roue
comme un ensemble.
IC593000PUNTI DI RIMOZIONE
IC523101
Ruota posteriore
1. Togliere:
9Ruota 1
NOTA:
Spingere in avanti la ruota e togliere la
catena di trasmissione 2.
IC513201
Cuscinetto della ruota (se necessario)
1. Togliere:
9Cuscinetto 1
NOTA:
Togliere il cuscinetto usando un estrat-
tore generico per cuscinetti 2.
IC594000
ISPEZIONE
IC514100
Ruota
1. Misurare:
9Scentratura della ruota
Fuori limite
Ripararla/Sostituirla.
2. Ispezionare:
9Cuscinetto
Ruotare l’anello interno con un
dito.
Ruvidità/Grippaggio
Sostituir-
lo.
NOTA:
Sostituire i cuscinetti, il paraolio e il
bordino della ruota come set.
Limite de voile de la roue:
Radial 1 1
: 2,0 mm
(0,08 in)
Latéral 2 2
: 2,0 mm
(0,08 in)
Limite di scentratura
della ruota:
Radiale 1 1
: 2,0 mm
(0,08 in)
Laterale 2 2
: 2,0 mm
(0,08 in)
Felgen-Verschleißgrenze:Senkrecht 1 1
: 2,0 mm
(0,08 in)
Seitlich 2 2
: 2,0 mm
(0,08 in)
5NY-9-30-5A 5/23/01 9:00 PM Page 7

5-4
CHAS
ROUE AVANT ET ROUE ARRIERE
VORDERRAD UND HINTERRAD
RUOTA ANTERIORE E RUOTA POSTERIORE
Disque de frein
1. Mesurer:
9Déflexion de disque de frein
(uniquement le disque de frein
arrière)
Utiliser le comparateur 1.
Hors spécificationExaminer le
voile de roue.
Si le voile de la roue est normal,
changer le disque de frein.
2. Mesurer:
9Epaisseur de disque de frein a
Hors limiteChanger.
Radachse
1. Messen:
9Radachsenbiegung
Abweichung von Spezifikation
Erneuern.
Die Meßuhr 1verwenden.
HINWEIS:
Der Biegewert entpricht der Hälfte der
Meßuhranzeige.
W
Niemals versuchen, eine verbogene
Achse geradezubiegen.
Axe de roue
1. Mesurer:
9Les flexions de l’axe de roue
Hors-spécification Changer.
Utiliser le comparateur 1.
N.B.:
La valeur de flexion est égale à la moi-
tié de la lecture du comparateur.
XG
Ne jamais tenter de redresser un axe
tordu.
IC514200
Asse della ruota
1. Misurare:
9Curvature dell’asse della ruota
Fuori specificaSostituirlo.
Usare il comparatore 1.
NOTA:
Il valore di curvatura equivale a metà
del valore letto dal comparatore.
T
Non tentare di raddrizzare un asse
piegato.
Limite de torsion de l’axe
de roue:
0,5 mm (0,020 in)
Limite d’usure de disque:
Standard Avant3,0 mm (0,12 in) 2,5 mm (0,10 in)
Arrière 4,0 mm (0,16 in) 3,5 mm (0,14 in)
IC594200
Disco del freno
1. Misurare:
9Inflessione del disco del freno
(soltanto il disco del freno
posteriore)
Usare il comparatore 1.
Fuori specificaIspezionare la
scentratura della ruota.
Se la scentratura della ruota è in
buone condizioni, sostituire il
disco del freno.
2. Misurare:
9Spessore del disco del freno a
Fuori limiteSostituirlo.
Limite di curvatura
dell’asse della ruota:
0,5 mm (0,020 in)
Limite di usura del disco
Valore normaleAnteriore3,0 mm (0,12 in) 2,5 mm (0,10 in)Posteriore4,0 mm (0,16 in) 3,5 mm (0,14 in)
Bremsscheibe
1. Messen:
9Bremsscheibenschlag (Nur
Hinterrad-Bremsscheibe)
Die Meßuhr 1verwenden.
Abweichung von Spezifikation
Schlag der Felge prüfen.
Falls der Felgenschlag inner-
halb des zulässigen Bereiches
liegt, die Bremsscheibe erneu-
ern.
2. Messen:
9Bremsscheibendicke a
Außerhalb des Grenzwertes
Erneuern.
Radachse-durchbie-
guhgsgrenze:
0,5 mm (0,020 in)
Bremsscheibe-
Verschleißgrenze:
Standard
Vorne3,0 mm (0,12 in) 2,5 mm (0,10 in)
Hinten 4,0 mm (0,16 in) 3,5 mm (0,14 in)
Limite de déflection de
disque:
Standard
Arrière—0,15 mm (0,006 in)
Bremsscheiben-
Schlaggrenze:
Standard
Hinten —0,15 mm (0,006 in)
Limite di inflessione del
disco:
Valore normalePosteriore—0,15 mm (0,006 in)
5NY-9-30-5A 5/23/01 9:00 PM Page 9